As a flexible, high-efficiency and high-precision automatic machine tool, a numerical control (NC) machine tool can comparatively well solve complex, precise, small-amount or multi-type machining problems, and is generally composed of a numerical control system, a main body and other auxiliary devices. The numerical control system being a core of the whole NC machine tool is capable of integrating position (trajectory) control, speed control and torque control altogether, executing parts of or whole numerical control functions according to code instructions, and realizing motion control of one or more machineries. As shown in FIG. 1, a numerical control system normally includes an input/output device, a NC device, a programmable logic controller (PLC), a servo system, a detection and feedback device and the like, amongst which the NC device is a hard core of the numerical control system.
The NC device may include a display module, an input/output module, a decoder, a motion planner, an axis motion controller, a memory and the like. The display module is an important medium for human-machine interaction, and provides a visual operation environment for users. The input/output module is a port for data and information exchange between the NC device and an external device, and is mainly used for inputting data such as NC machining programs, control parameters, compensation quantities and the like, and for outputting information such as servo drive, trajectory control and the like. The decoder is mainly used for decoding program segments of the NC machining program. The motion planner mainly facilitates speed processing and interpolation operation. The axis motion controller is an interface module between the NC device and a servo drive system and operates for position control. The memory is used for storing information such as machining programs, system configuration parameters, system inherent data and the like.
At present, functions of the numerical control system are required to be flexibly expanded, and a conventional NC system normally employs an architecture formed by a personal computer as an upper computer, as well as a NC as a lower computer, as shown in FIG. 2, the upper computer and the lower computer are both disposed in the vicinity of a machine tool and connected to each other via a bus. The upper computer (PC) is an HMI for handling non-real-time tasks of the system, and the lower computer (NC) comprises a NCU and a PLC both for handling real-time tasks of the system, such as motion control and logic control. The numerical control system possesses a distributed characteristic, and partly supports secondary research and development by users and independent upgrading. Moreover, a control end of the system as well as the PC end of the system are open, and communication between the upper-computer and the lower-computer, and control thereof can be easily realized and maintained.
However, with increasing demand for intelligence and multi-functionalization of the numerical control system, requirement for hardware thereof becomes much higher. Particularly, as functions of NC-related software, such as Computer-Aided Design (CAD), Computer-Aided Manufacturing (CAM), Computer Aided Process Planning (CAPP), Computer-Aided Engineering (CAE), Product Lifecycle Management (PLM), Manufacturing Execution System (MES), Enterprise Resource Planning (ERP) and the like become much more powerful than before, more and more computer resource for running the software is needed, and correspondingly, there is much higher requirement for a kernel and a memory of the numerical control system. If the requirement for intelligence and multi-functionalization of the numerical control system is met at the cost of continually upgrading software and hardware thereof, on the one hand, cost on design, manufacturing, upgrading and use thereof may be significantly raised, and difficulty in testing, development and production thereof may be increased, and on the other hand, the numerical control system may become bloated, complex and unreliable. Additionally, functional parts of the numerical control system under this architecture and other numerical control systems are mutually independent, this architecture with completely opened interior and relatively closed exterior cannot meet requirement for an external equipment or software and expanding functionality thereof. Furthermore, this architecture forms a local resource island, resulting in poor compatibility between the numerical control system and the external equipment or software, and thus partly restricting multi-functionalization of the numerical control system.
At present, the numerical control system having the above-mentioned architecture makes it difficult for intelligence thereof to adapt to increasingly complex manufacture process, and thus becoming a main bottleneck during development of the numerical control system towards intelligence digitalization and multi-functionalization.